The Bitcoin price increase has three factors.

[zubrr51]

As the theory of Charles Dow says, in the price movement all the factors of the past, present and future are already laid.

[Herbys]

No. 1 is the amount of transactions between buyers and different people. For example if you have 100 BTC you want for $ 1, but someone with 100 BTC want to sell for $ 2, the value it will increase so.
Secondly because of the rare bitcoin copper, and the need to use BTC for various purposes so many people need BTC that makes the BTC increase.
Third, by speculation, those who have money to inject money into the market and use FOMO tactics to entice more and more people into the market, the price will be pushed up.
There are many other factors, but only focus on the three main good.

The cost of Bitcoin depends only on the level of trust in it. You may want 100K for 1 BTC, but no one will give this price.

So, if I own Bitcoin, which now costs $ 1, in a year or two it can still be $ 1, $ 1000 or zero.

[nazaididuan1]

The price of BTC fluctuates due to supply and demand! Bitcoin is a new thing, and the degree of market acceptance is very important.
When the total output of Bitcoin approaches a constant value, its value can be truly stable. At this point, we can verify that it can take on the responsibility of becoming a hard currency.